Screw-threads  by chasers



E. M. WILDEY.

DEVICE FOR cunme SCREW THREADS BY CHASERS.

' APPLICATION FILED FEB-M1918. v 1, 3 1 3, 568. Patented Aug; 19, 1919.

3 SHEETS-SHEET I.

- Amwa fer E. M. WILDEY.

DEVICE FOR CUTTING SCREW THREADS BY'CHASERS.

APPLICATION FILED FEB- I. 1918.

1 3 1 3, 5 68 Patented Aug. 19, 1919.

3 SHEETS-SHEET 2.

I rvue/nior Edward, M. Wildey.

W Altering.

E. M. WILDEY.

DEVICE FOR CUTTING SCREW THREADS BY CHASERS.

APPLICATION FILED mm. 1918.

1,313,568. 4 Patented Aug. 19, 1919.

3 SHEETS-SHEET 3.

[ma/enter 1 Ed ard mlday. Br ma;

EDWARD MIn'roN ILDEY, F CANONBURY, LONDON, EnGLANm nnvrcnnon CUTTING scREW-rHnEAns BY ci-rnsnns.

. Applicationfiled February 1, 1918.1 Seria1No. 21 5,012.

To all 107mm .z' t ma concern .1

. Be it known that. I, EDXVARDUMIIIHQITON WILDEY, a subject of His Majesty King George V of the United Kingdo'mof Great Britain and Ireland and of the British; Dominions beyond the Sea and Emperor of Y I ndia, residing at Canonbury, London, Eng.-

land, have invented certain new and useful Improvements in Devices for Cutting. Screw Threads by Chasers, of which the, following is a specification. v

The present invention relates to improves ments in chaser. holdin or serving devices as described in the speci cationof my United States. application-[Nd 2Q3',286' dated 21st Novern b'ery 19117. In that specification No. 203,286 there is; described a dupl'eX or balanced supporting control device forchasers awb comprisin two chaser holders, each on a; rocking uprig t e, c, with eccentrics 9,; g for the adjustment of height, the uprights being made to approach or recede by a lever hinged to a support,: for example, a crane arm is rising fromthe base plate clear of the Work, the intermediate mechanismv con sisting of links m, m which are drawnor pushed by adoubleeccentric system attached to the axis land shown; at a, n, and a-locking pawl, operating into. a toothed are plecep. v

The improvement according to thelpresent invention consists embodying such mechanismas shall enable the chasers to out so as to finish the screw close to a face, then automaticallyto recedethe chasersout o f cut ting range when the face is reached, and also allovvthe lathesaddleglto which the device is fixed) to move forward 1 some" distance while the chasers remain against the face but recededfrom the cutting range of the I work.

described in my previousspecification is Figures 1, 2 and 3 represent the present improvement, Fig. l being a front View;

that elevation of the device which .approaches or recedes from thenose of the.

lathemandrel being regarded as the front. Fig. 2 is a sectional view, at A, A, of Flg. 1. Fig;3 is a back View, or as seen from the puppet end of the lathe bed.

In the drawings like references areused toindicate like parts of the device illustrated in. thea-aforesa prior specification No.

In, carrying out the present improvement the base plate 0 ofthe-chaser holder or server made double, 0 and c and with suitably formed grooves or Vs so thatthe portion Q2 may slide parallel: to the axis of the lathe independently ofthe portion 0' which is attached to the saddle of the lathe.

The crane arm is ('or as depicted a: double ar1n7c,,7t" with a common end) carries in its lower portionf a horizontal sliding bolt That end of the vbolt' q which is nearest the face at which the thread finishes is fitted with an adjnstable' feeler r on which is mounted an eccentric collar or rim 1", while the other end of the bolt keys into a spring; actuated vertical sliding bolt' or bolt-system s' which has its bearings in' one ofthe' lugs d of the chaser holder base. The keying at the end of the'horizon'tal bolt Q working in the vertical bolt sis shaped" so as to allow the vertical bolt or bolt-system to, rise by tension of the spring 8 when the horizontal bolt 9 is moved backward against the tension. of

itspring'g. The lower end of'the' vertical bolt or boltsystem 8 may be tapered so to more readily enter a. corl'espondingly ta- .ered recess in 'theauxiliary base 0. thuslockii' g together'the two base elements 0 and 0 Immediately over the top of the vertical bolt or bolt system, and in contact therewith, is a curved'leverfl, t t This lever is fulcrii'me d. in the crane arm about midway ofits curve at 25 The upper end of the lever is formedas' a pawlwhich engages a ratchet 10 formed on the boss of the arm 2'. The boss is surrounded by a coiled spring 2' onie'end of Whichi's fastened to' the crane arm. or double arm 1a,, 76 and theother end of which is fastened to the arm 2'. may" be placed between a projection .u on the under. side' ofthe chaser holder base'c and thefsiol'e 'v" of an elongated recess o, in the auxiliary base 0, But ordinarily any such A spring intervening spring may be dispensed with and, as shown, contact of the projection'u with the side '0 of the recess '2) is arranged to reg'ifster the bases for locking together by the bolt system 8. A horizontal lever w passes through a slot in the chaser holder base, and has one of its ends pivoted on the auxiliary base; the other end of the horizontal lever conveniently has a handlefor operating. During cutting operations, the two bases are' locked together by the lower end of the vertical bolt or bolt system s.

Thevertical bolt or bolt system 8 which is illustrated consists of a hollow bolt-s adapted at theylowerand open end to engage' a socket s in the slide guide or auxiliary base 0' and having at the upper and perforated end a saddle-like piece .9 into which the corresponding and flat end of the bolt 9 enters for locking and releasing a bolt 8 which is slidably mounted in the perforated upper end of the bolt 8 and the top of the saddle piece 8 and adapted to be held retracted by the flat end 9 of the bolt 9 engaging in the recessed end of the bolt 8 When the bolt 9 is moved backward, a notch g frees the bolt 8 for rise by the pressure of the spring 8 interposed between a collar on the shank of the bolt s and a transverse pin 8 which runs through slots in the two bolts, the arrangement being such that first the lever is raised by rise of the bolt s 1to withdraw the pawl t and release "the ratchet p which holds the chasers to duty, and when the back pressure which tendsto bind the bolt 8 having been thus relieved,

, the further upward movement of the bolt '8 in'contacting'through the intermediary of 7 its shoulder with the perforated end of the bolt s raises the bolt 8 clear-of its socket 8 The operation of the improved device isas follows i The auxiliary base is fastened to the saddle of the lathe, and the two bases are locked to gether by the lower end' of the verticalbolt or bolt system 8. The eccentric rim on the feeler head of the horizontal bolt 9 is so adjusted by rotation that when the chasers have arrived at the face, the horizontal bolt has moved backward to its full limit and its appropriately shaped end which keys into the vertical bolt or bolt system 8 is then in such a position that the vertical bolt is freed for vertical movement, ancljis forced upward by its spring. In the same upward movement the end of the bolt or bolt system 8 is withdrawn from the auxiliary base immediately the upper end of the vertical bolt or bolt system 8 has moved the curved lever t, 2 t to withdraw its pawl end out of engagement with the ratchet; and so release the ratchet for backward movement under the impulse of its coiled spring 11. The chasers are thus receded from thework and as the bases are free to move relatively, the motion of the lathe saddle may continue while the lathe is being reversed or stopped. Before commencing operations 'again the two bases are brought into locking position by the horizontal lever provided andlocked by the vertical bolt being pressed 'down'by the curved lever. When the curved lever is pressed down and in looking position the horizontal sliding bolt 9 movesforward un der the pressure of the spring 9 and locks the vertical bolt in retracted position. i

What I claim is: i H 1. In a, device ofthe class described the combination of. a lathe saddle, asupp'orting control device or server for chasers, a slide guide connection of the device or server to the saddle, mechanism for locking said de vice to the lathe saddle, mechanism for holdmg the chasers to duty, and releaslng mechan1sm for said locking and holdingmecha-- nism, said releasing mechanism operatively co-acting with a faceor flange of the work, substantially as described.

2. In a device of the class described the combination of a lathe saddle, a supporting control device'or server for chasers, a slide guide connection of the device or server to the saddle,'.locking mechanism for locking the device or server to the lathe saddle, said locking mechanism comprising. a vertical bolt system, and a horizontal retaining bolt therefor, a feeler operatively contacting with the face orfiange of the workfor releasing said retaining bolt and locking mechanism forthe chasers controlled by said bolt system', substantially as described.

3;In a device of the class described the combination of a lathe saddle, a supporting control device or server for chasers, a' slide guide connection of the device or server to i the saddle, locking. mechanism forlo'ckin thedevice' or server to the lathe-saddle, sai lockingmechanism comprisin a verticalbolt system, an actuating spring'th'erefor, a horizontal retaining bolt engaging said vertical bolt system, .an adjustable feeler operatively contacting with the face or fiangeof the work for releasing said retaining bolt, and

p locking mechanism for the chasers controlled by saidbolt system, substantially'as described.

' 5. In, a device of the class described the combination of. a lathe saddle, a supporting control device orserver for chasers, a slide guide-connection of the device or server. to

the saddle, locking mechanism for locking the device or server to the lathe saddle, said locking mechanism comprising a vertical bolt system, an actuating spring therefor, a

horizontal retaining bolt engaging said vertical bolt system, an adjustable feeler op'er atively contacting with the faceor flange of the work for releasing said retaining bolt, and locklng mechanism for the'chasers com,

prising a spring controlled ratchet, a locking pawl, and areleasing' lever therefor, said lever being controlled the bolt system,

substantially as describe 6. In a device of the class described the combination of a lathe saddle, a supporting control device or server for chasers, a slide guide connection of the device or server to the saddle, mechanism for locking said device to the lathe saddle, mechanism for holding the chasers to duty, releasing mechanism for said locking and holding mechanism, said releasing mechanism operatively co-acting with a face or flange of the Work, and means for restoring the parts to operative position after release, substantially as described.

In testimony whereof I aflix my signature.

EDWARD MILTON WILDEY.

Copies 01 this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. G 

